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By R. A. Metz, M. A. Bryant, J. C. Goodwin, T. B. Faddies, L. D. Kornze

The Mercur Gold Mine is located 56 km (35 air miles) southwest of Salt Lake City in north central Utah. In July 1981 Getty Mining Company made the decision to put Mercur into production. The first gold bar was poured in April 1983. This paper provides details on: 1) the history of the camp, 2) past production, 3) geology of the deposit, 4) the exploration and development program, 5) ore reserve estimates, 6) detailed geologic pit mapping, 7) production blasthole sampling techniques and 8) the use of geostatistics (kriging) in handling assays and gold extractions to produce the required mill feed.

Jan 1, 1992

By E. D. Attanasi, M. W. Bultman, J. H. DeYoung

The 1987 recovery in the US mining industry permitted modest increases in exploration expenditures that year (Fig. 1). Favorable market conditions apparently allowed the gains to be sus¬tained in 1988. There was great uncer¬tainty early in the year as to whether world and US economic growth would be a casualty of the October 1987 worldwide stock market crash. By nearly all measures, the performance of the US minerals industry was strong¬. A weak US dollar and the strong growth of worldwide capital spending resulted in in¬creased US exports of con¬sumer and producer durable items as well as strong domes¬tic demand for metals. In fact, 1988 US steel industry exports reached levels not attained since the mid-1970s. It was re¬ported that steel industry labor productivity is now roughly twice the 1981 level. Among metals with signifi¬cant average nominal price increases in 1988 over 1987 levels were copper (43%), alu¬minum (52%0), and zinc (44%). Even though domestic copper production has grown since 1984 by 30% in mining and 24% in refining, em¬ployment in mining and milling is 4% below the 1984 level. Domestic unit costs are reported in the range of $1.10 to $1.33/kg (50 to 60 cents per lb). The US base metals industry is proba¬bly in its best cash position in many years. However, there has not been a large increase in exploration expendi¬tures. This is due mostly to the percep¬tion that worldwide capacity can easily be increased. Industry reports do show that "low cost" copper producers have been buying reserves from weaker com¬panies. The 1987 Society of Economic Ge¬ologists (SEG) survey of exploration activity indicated that 95 cents out of every exploration dollar spent by US and Canadian firms was for base and precious metals (Economic Geology, January 1989). Press reports, though, make it clear that most of that spending was targeted for precious metals. US claim staking data (Fig. 2) rein¬forces this suspicion. The apparent lag in new claim filings in Alaska and phe¬nomenal growth in filings in the lower 48 states suggests that exploration is directed at relatively low risk targets. In the conterminous 48, more than 40% of the new claims were made in Nevada, indicating an emphasis on gold (although even Nevada had some base metals exploration). Even with a price decline during 1988, the difference between the gold price and average global "cash" production cost of $7.30/g ($227 per oz) still leaves room for an attractive return (Northern Miner, 1988). Exploration plans and results Metals Economics Group (Halifax) indicated in its 1988 exploration survey that exploration expenditures by US and South African firms would be at about 1987 levels. It also reported that Canadian and Australian firms were ex¬pected to reduce their exploration spend¬ing significantly. Firms in both coun¬tries were caught in changes in tax laws. In Canada, the Mining Ex¬ploration Depletion Allow¬ance (MEDA) once permitted generous tax write-offs to in¬dividuals investing in miner¬als exploration. It was to be replaced in January 1989 with the Canadian Exploration In¬centives Program (CEIP). Although structured and ad¬ministered differently than MEDA, CEIP can provide an equivalent or possibly greater financial incentive for min¬eral exploration, for junior mining companies. In 1987, it is estimated that junior com¬panies accounted for two¬-thirds of the off-property (or grass roots) exploration ex¬penditures in Canada. Australia will revoke the tax exemption for gold in 1990. Australian operators, therfore, were expected to concentrate efforts on speeding up pro¬duction during 1988 and 1989. In 1988, Chile and Mali announced special efforts to attract gold explora¬tion by foreign companies. The Cana¬dian government continues to express concern about the write-off (and drawdown) of base metal reserves. Falconbridge did announce a new initiative to identify additional base metal reserves in the Sudbury district. Discoveries Gold deposits dominated discoveries

Jan 1, 1989

By Gordon M. Pugh, David G. Rasmussen

INTRODUCTION Variations of cut-and-fill stoping are the most com¬monly used methods for mining narrow, nearly vertical veins in the United States. These methods offer the best results for maximum recovery with minimum dilution of ore from veins that are irregular along either the strike or dip. The vein is developed along the strike length in 61 to 122-m (200 to 400-ft) blocks or stopes and vertical lifts of 48 to 61 m (160 to 200 ft). The level development is either on the vein or parallel to the vein with crosscuts intersecting the vein at right angles. Chutes, manways, and haulageways are established in the center of the stopes at the lower level of the ore block. Mining then proceeds by blasting down horizon¬tal cuts of the vein in both directions from the chutes. As the blasting continues to the outer limits of the stope, the broken ore is slushed into chutes. When a complete horizontal cut has been made, the service raise, including chutes, is raised to a height of a few feet from the back and the stope is filled with either sand fill or waste rock. Then the mining cycle is re¬peated until the stope reaches the level above. LEVEL DEVELOPMENT PRACTICES FOROVERHAND CUT-AND-FILL STOPING The two basic methods used are: the development of the haulage drift within the vein, or development of the haulage drift paralleling the vein in the foot or hang¬ing wall with crosscuts intersecting the vein perpendicu¬larly at 61 to 122-m (200 to 400-ft) intervals. The il¬lustrated methods of development show some of the variations which can be used to develop a stope block. Development for cut-and-fill stoping does not require the more elaborate schemes outlined for shrinkage or sublevel long-hole stoping. Many factors must be considered before deciding on a particular development plan and usually the nature of the vein or host rock will dictate which specific method to use. If the vein is relatively straight, then develop¬ment on the vein is feasible. Excessive ground pressures will necessitate the leaving of a sill pillar (Fig. la) and highly fractured or "heavy" ground will require timber¬ing (Fig. 1b). Development on the vein has the advan¬tage of reducing capital outlay and waste handling prob¬lems since the mined rock has value. But removal of the sill pillar is costly and time-consuming. Also, where no sill pillar is left, excessive timbering and subsequent level repair is a drawback. Development in either the footwall or hanging wall is the more common procedure and offers greater flexi¬bility in overall development of consecutive stoping blocks by partially disassociating the level development from stoping (Fig. 2). Chutes, manways, and service compartments com¬prise the next stage of development and are established in a variety of ways. They provide access to the stope, ventilation ducts, and muck removal. Several different development systems are in common use and average costs for each have been developed. Raise borers are used to establish ventilation and ac¬cess from level to level. They are normally reamed with 1.5 or 1.8-m (5 or 6-ft) cutterhead and may either be left bald or lined with a 1.2-m (4-ft) diam corrugated liner plate, depending upon ground conditions. The use of an Alimak raise climber is another effec¬tive method of driving a raise from level to level. The size usually is 2 m (7 ft) square. This will accommodate square-set timber which is later installed. This method of raising is not common, although it is a valuable tech¬nique especially when level spacing is several hundred feet.

Jan 1, 1982

By D. E. Ranta, M. G. Hester

The ore reserve modelling of stratiform uranium deposits to be mined by selective underground mining methods must be done with consideration of the erratic nature of the ore-forming processes that produced the mineralization. Estimation methods that model the uranium grade as a smooth transition between high-grade and low-grade drill hole intercepts tend to greatly overestimate the ore tonnage. Care must be taken to first establish realtistic ore pod geometries and then estimate the grade of the reserve units within the pods.

Jan 1, 1992

By O. Tsuge, G. Hoffman

ITmk3®(Iron Technology Mark III) is an innovative new ironmaking technology whereby high quality iron nuggets are produced directly from iron ore fines and coal in a rotary hearthfurnace1). The reaction mechanism has been investigated in detail through fundamental laboratory research2)3), and the ITmk3 process has progressed from the laboratory to commercialization by the success of the pilot plant tests initiated at Midrex’ Technical Center and at the Kakogawa Bench Plant (KBP) located at Kobe Steel Ltd. Kakogawa Steel Works4)5). Pilot operations have demonstrated rapid production of the iron nuggets with complete metal/slag separation at a relatively low operating temperature. The Kakogawa Bench Plant (KBP) in Japan has logged 21 days continuous operation during which high quality iron nuggets were produced directly from fine ore and coal. The operation technology and the engineering data obtained from these pilot tests were instrumental for the scale-up of the ITmk3 process for the Mesabi Nugget Corp. pilot demonstration plant, which is located at Cleveland Cliffs Inc. Northshore Mining iron ore pellet plant in Silver Bay, MN. The ITmk3 process is an ideally suited technology for siting at the iron ore mine, as it allows the economical production of a value-added merchant iron product.

Jan 1, 2003

By M. Scherzinger, M. Dr. Mazurkiewicz

Additional progress in comminution can be achieved if the compressive crushing principle commonly used at present is changed to one where particles are fragmented by the tensile growth of preexisting internal flaws or cracks, under internal waterjet pressure. This idea was studied in a number of tests and generated results and conclusions are the subject of this paper. It covers tests with different jets imposed on rock samples during compressive load as well as without any loading.

Jan 1, 1992

By C. McDonald, S. Slottee

Deep "paste" thickeners have been used in the alumina industry for several decades to improve chemical recovery and allow “stacking” of the red mud for disposal. These paste systems have eliminated many traditional tailings ponds in addition to providing better tails washing and better water recovery. This technology is not widely used or understood in other mineral processing applications. However, there is growing worldwide recognition of the advantages of concentrating mill tailings to a “paste”, i.e. a solid suspension that does not settle or segregate. This technology offers several alternatives to the traditional tailings pond such as “stacking” or mine backfill. More water recovery is possible than with high rate thickeners. Process benefits come in the form of better chemical and metals recovery through better washing in counter current decantation (CCD) applications. Obtaining a true paste (non-segregating suspension which exhibits a yield stress) and understanding the handling characteristics for applications outside alumina, are recent developments. Achieving all of the benefits available from a paste system requires careful design that takes into account the specific requirements of the disposal application along with the peculiar difficulties in producing and handling paste. In fact, design of a paste system is markedly different from a conventional system. Project design usually requires the cooperation of experts in several interrelated specialties including geotechnical, thickener design, pumping and discharge design and controls. A successful project must coordinate all activities to ensure that the overall objectives for the project are achieved. This paper describes the properties of paste, reviews the applications, and discusses the design of a complete paste deposition system.

Jan 1, 2003

The Northside Storage Tunnel Project in Sydney includes over 20 km of TBM driven tunnels, over three km of declines and major caverns and pump rooms. The paper describes methods used for design on the project. Emphasis is given to the refinement of the use of empirical rock mass classifications, and to the use of discontinuum numerical methods. The use of empirical rock mass classifications in Sydney sandstone has usually led to conservative design because the systems are based on a random orientation of joints in the rockmass. Because the joint sets are usually oriented in a way that is beneficial for tunnelling, limits must be placed on the parameters used in the classifications system. The paper discusses these limits and the derivation of the parameters. The use of numerical methods in Sydney sandstone is discussed. Continuum methods have their uses, but discontinuum methods are preferred. The use of UDEC has been validated against a previous project, the New Southern Railway. Recommendations are given for UDEC models. In Sydney's geology, so advantageous for tunnelling, the challenges of this project have been to make the best use of the good conditions, while maintaining safety for the workforce and the future operators of the project.

Jan 1, 1999

By R. Tanaskovic

Unfavourable climatic conditions in stopes are of significant economic and social importance due to the following reasons: - Working effect is much lower leading to decreased output and work productivity disregarding implementation of mechanization. - Manpower operating capability decreases much faster under unsatisfactory climatic conditions. Under normal climatic conditions a workman would expend much less effort in line with a shorter effective time for the achievement of identical production effects since the work would be more efficacious. The objective of study of problems and climatic conditions is to make the working environment in mines suitable for normal development of operations. Lowering of mining works to increasing depths and winning of a growing number of small orebodies over a broad area makes the problem of creating suitable climatic circumstances more complex. Mining costs are growing due to bench conditions in line with decreasing metal content in the ore, so frequently the investments required for creating favourable climatic conditions represent, in addition to the selection of mining technology, a very important parameter when making decisions regarding exploitation. As known, the basic factors affecting climatic operating conditions in mines-are: temperature, humidity and speed of air flow, implying that the climatic operating conditions are closely related to mine ventilation. Usually, the concept of unfavourable climatic operating conditions includes increased mine air temperature and humidity and low air flow velocity so that heat exchange between human organism and the working environment is impeded or reduced to minimum. Metal mines in Yugoslavia are characterized by the existence of a large number of active faces - stopes and horizons and lowering of mining operations to increasing depths, so that face ventilation solutions are more and more complex. Since its foundation (1961), our Institute is engaged in investigation of factors influencing climatic circumstances improvement of calculations for air distribution and distribution control in complex ventilation networks and study of problems related to ventilation of large volume and irregular configuration faces, as well as application of gained knowledge in our mines. The paper presents the knowledge and experience gained in the case of Lead and Zinc Mine "Trepca" - Stari Trg.

Jan 1, 1980

By Robert D. Hansen, Basil S. Fee, Richard R. Klimpel

Despite the importance of froth flotation to the mineral industries as a means of separating various minerals, the commercial flotation reagents used have varied little in the last twenty years. Numerous articles and books are available describing existing flotation chemistry and its application, e.g., Fuerstenau (1962), Fuerstenau (1976), Aplan (1980), Somasundaran (1980), King (1982), Leja (1982), Ackerman, et. al. (1984), Crozier (1984), Hansen and Klimpel (1985). There are many reasons for this lack of significant new reagent development including the general utility and relative cheapness of collectors, such as xanthates, and frothers, such as methyl isobutyl carbinol and the glycol ethers. Another important reason is the inherent complexity of the flotation process itself coupled with highly variable and difficult to standardize feed materials which make reliable reagent comparisons difficult and seriously limit the use of theoretically based studies to "predict" new or optimal reagents. In addition, the higher cost of "specialty flotation reagents demands that their performance attributes be significantly greater than existing general all- purpose commercial reagents – something often difficult to prove in practice. Faced with this situation, a detailed applications research pro- gram [Klimpel (1980 ab, 1982, 1984 ab), Klimpel, et. al. (1982)] was organized from 1979-1985 on mineral flotation with the following goals: 1) the development of appropriate batch laboratory flotation testing techniques sensitive enough and statistically reliable enough to identify small differences in performance between different flotation tests (i.e., between various reagents, even those with relatively minor chemical structural changes); 2) the identification of mathematical models with appropriate numbers and types of parameters that have maximum statistical power to statistically distinguish between various time-recovery profiles; 3) the generation of laboratory and corresponding plant scale data in sufficient quantity and consistency so that the highly interactive nature of the "flotation system9' of chemistry/ equipment/operating conditions could be quantified; and 4) the invention and development of really new and unique reagents for giving improved flotation performance. The goal #1 was achieved [Klimpel (1980b. 1984b), Meyer and Klimpel (1984)l by basically using a simple automated paddle device for consistent

Jan 1, 1986

By R. Herrera-Urbina, D. W. Fuerstenau

A large number and a wide variety of chemical reagents are used in flotation processes for wettability and Eh control, particle agglomeration/dispersion and bubble stability. A historical account of the use of flotation reagents through the years since flotation was introduced as a viable and economic process for the concentration of sulfide minerals is given and a review of old and modern postulates of their interaction with minerals is presented. Although the results of surface and colloid chemistry studies with well characterized mineral/flotation reagent systems have advanced our understanding of the role played by these chemicals in the flotation process, many questions remain unanswered. Moreover, new flotation reagents are needed to solve the challenge posed by the treatment of problematic-type ores and fuel deposits that have increasingly become the source of our raw and energy materials. Because of the depletion of high-grade and relatively easy-to-process ores, flotation scientists and engineers are confronted with finding more specific and selective flotation chemicals to effectively and economically concentrate minerals. The development of new flotation reagents is vital for cleaning fine coal and processing polysulfide, polymetallic ores, and mixed oxide/sulfide ores.

Jan 1, 1989

By George M. Meisel

This paper is devoted to a discussion of the factors governing design of concentrators for large grinding circuits. Emphasis is placed on the manner in which use of ever larger grinding mills has affected the size of grinding bays, service cranes, gear reducers and electric motors, and the selection of ancillary equipment for cushioning of the starting load of large mills. Information is presented on the effect of using large grinding mills on the capital and operating costs of concentrators, e. g. : (Fig. 1) ? Benefits in lower cost of mills, drives and materials handling equipment, plant space, power, grinding media, operating labor and maintenance, and in ease of instrumentation and automation. ? Penalties in distribution of materials from the grinding mills to multiple lines of equipment which have not been developed to commensurately large sizes, and higher cost of ancillary equipment.

Jan 1, 1968

By Robert C. Cifelli

INTRODUCTION Background and Objectives Underground coal mining is a vital component of West Virginia's economy. However adverse environmental effects including ground subsidence and aquifer dewatering are often associated with such mining activities. Many families in northern West Virginia still rely on private water wells and springs for domestic water needs. In such areas where underground coal extraction and land subsidence have occurred, a disruption of the ground water flow system commonly exists with subsequent drainage of water to lower levels that may extent as deep as the mine workings; this causes loss of water supplies to landowners and represents a nuisance to mining companies 2 This report represents a summary of an M. S. thesis project in geology at West Virginia University by the senior author (3). The intent for this study was to document the effects of underground coal removal on ground water levels at selected mine sites in northern West Virginia, as observed from water wells, springs, and streams. This research should be useful to coal companies and regulatory agencies and aid in recommendations of future water well locations and specifications in areas of existing or proposed underground coal mines.

Jan 1, 1986

By K. H. McDaniel

This paper describes the development of a Windows-based interactive mine ventilation simulation software program at the Waste Isolation Pilot Plant (WIPP). To enhance the operation of the underground ventilation system, Westinghouse Electric Corp. developed a program called WIPPVENT. While WIPPVENT includes most of the functions of the commercially available simulation program VNETPC from Mine Ventilation Services Inc. and uses the same subroutine to calculate airflow distributions, the user interface was completely rewritten as a Windows application with screen graphics. WIPPVENT is designed to interact with WIPP ventilation-monitoring systems through the sitewide central monitoring system. Data (e.g., air quantity and differential pressure) can be continuously collected from the underground ventilation remote-monitoring and control system and from the mine's weather stations (psychrometric data). Furthermore, WIPPVENT incorporates regulator characteristic curves specific to the site. The program utilizes this data to create and continuously update a real-time ventilation model. This paper discusses the design, the key features and the interactive capabilities of WIPPVENT.

Jan 1, 1997

By Peter G. Chamberlain

Novel and innovative mining methods are attracting the attention of mining engineers at an unprecedented level. Historically, the US mining industry has responded rather conservatively to new technology. The financial difficulties affecting the domestic mining industry in the early 1980s changed attitudes toward new technology. The market contraction during that period, coupled with an expanding world mine capacity, created a serious oversupply of many raw mineral products. Many mining companies found that retaining a share of world markets while making a profit required drastic cost-cutting measures.

Jan 1, 2008

By Robert J. Ramsey, N. Finkelstein, Robert D. Jeppson

Introduction The Utah Copper Division of Kennecott Copper Corporation will present its contribution to the A. M. Gaudin Flotation Symposium in four parts. The first two segments will discuss briefly the historical development of the Utah Copper Division and describe the ore body. The third segment will review the facilities and operating procedures for the Utah Copper Division's newest plant, the Bonneville Concentrator. The fourth segment describes flotation process circuitry, including molybdenite recovery procedures, at the Arthur and Magna concentrators. (The Bonneville concentrator is a crushing and grinding unit and does not have its own flotation plant). 1. Historical Development Progress through change has been the key to the successful operation of the Utah Copper Division for more than 70 years. As the original low-grade copper operation, the pressures to remain competitive and profitable have dictated the timing and extent of each change. Much of the change has occurred through technological and economic advancements in the area of ore concentration. The Utah Copper Division of Kennecott Copper Corporation had its origin June 4, 1903, when the Utah Copper Company was organized. The initial mill of 300 tpd (tons per day) capacity was built at Copperton a few miles below the present Bingham Canyon mine site. From 1904 to 1910, the Copperton mill was expanded to a capacity of 1,000 tpd, and all of the known apparatus for gravity concentration were evaluated.

Jan 1, 1976

By Terry McNulty

There are many potential pitfalls in the commercialization of innovative technology. The failures often are remembered longer than the successes, thereby serving as deterrents to subsequent attempts. The mineral industry's future depends on effective innovation. So it is essential that the causes of failure are understood. Innovation can be examined equally well in the context of geophysics, geology or mining. However the author's experience has been in mineral processing and chemical engineering. So the following discussion is limited to processes and/or plants for producing mineral concentrates, metals or inorganic chemicals. More of what follows has to do with underachievement or failure than success. But this article demonstrates that there is a strong element of predictability in the former. Furthermore, it is a credit to the minerals industry and to the engineering profession that a very high percentage of projects succeed in achieving design capacity and forecast operating costs. Innovation means the introduction of something new. In this article, the words "innovative technology" are used broadly. They include new processes and novel combinations of established unit operations, as well as novel types of processing equipment or largest-ever equipment models. The discussion of project outcomes is based on personal experience or on published information. Citations are given for technical publications that provide either project information or insights into the methodology used to analyze project performance. However, specific projects have not been identified due to the rather negative connotations of some of the conclusions drawn about the less favorable outcomes.

Jan 1, 1998

By K. T. Valsaraj, L. J. Thibodeaux

Solvent sublation, the separation process for the removal of two hydrophobic compounds (penta- and trichlorophenols) from the aqueous phase, is discussed, as is a steady-state mathematical model for fire process. Solvent Sublation "'as conducted in a continuous countercurrent mode. The underlying mechanisms, theory and experimental details on the effects of process variables on removal efficiency are reported.

Jan 1, 1994

By B. V. Knelson

Although the concept of centrifugal recovery has been around in one form or another for many years, it has not been until recent times that it has became clearly understood am properly put into perspective. Simplistic in theory, it is when one begins to examine the variables involved that the true complexities of this matter begin to emerge. In creating an enhanced g force concentrator, there are many aspects both positive and negative that are encountered.

Jan 1, 1989

By S. Bhattacharaya, S. Aich, B. K. Nandi

"At present scenario, there has been an increasing demand in the usage of blend coal in power sector; regardless of how, specific knowledge on burning and ignition characteristics and their interactive effects is stingy. In this work a detailed investigation was therefore taken up to study in detail the combustion characteristics of selected coal samples and their blends. Certain parameters were believed to have significant effects on combustion characteristics of individual coal and their blend. Major parameters identified for this purpose included proximate analysis, combustion conditions, heating rate, reaction regions, blending ratios, ignition condition, reactivity (or reaction rate) and burnout temperatures. With the help of these parameters, thermal features and reaction kinetics of the individual and blended samples were investigated through a qualitative and quantitative thermo-gravimetric analysis of two different individual coals and their blend carried out in an oxygen atmosphere from ambient to 800 0C at a constant heating rate of 10 K/min. A significant difference in terms of rate of mass loss with temperature correlated from Arrhenius expression along with coal-coal blend interactions and deviation from their expected behaviour, have been observed between the kinetics of individual and blend samples, the latter showing better ignition performance and comprehensive combustion phase. It was also found that particles having the lowest percentages of volatile matter and ash could possibly be blended with particles having high ash and volatile matter to meet the required burning condition which can be effective in terms of cost savings, improved fuel economy, reduced undesirable exhaust emissions and improved safety of coal burning equipment. Experimental results further indicated that individual samples and coal blend samples have different combustion features in terms of residue left, peak temperatures and activation energies. Thermodynamic activation parameters such as activation energy, pre-exponential factor and order of reaction were computed from the thermal data using the modified form of non-isothermal methods. INTRODUCTION Coal has been the most significant source of energy for India and would remain so at least for the next few decades. About 60-65% of the electricity produced in India is from coal fired power plants. Indian coal is of drift origin and of high ash content. Ash content of the coal burnt in power plants in India is in the range of 30-45%, most of it being Run-of-Mine coal. Most of the power plants in India source their coal from number of mines, most common being multiple sourcing. Usually coal from each source [1] is burnt separately. For various reasons mostly associated with logistics, burning of blended coal is rarely practiced. Blending of coal is practised mainly for improving the quality of available coal and meets the shortage of coal supply. Blending technique is generally practised in power industries to reduce the cost of power generation along with mitigating combustion performance or slagging problem ensuring consistency in as fired coal quality and also for environmental compliance. Blending good quality imported coal can improve coal quality and helps in preserving indigenous coal resources for longer period [2]. Use of blended coal shall reduce load on all boiler components (Mill, CHP, Boiler, AHP) & reduce O&M cost and increase the availability. The main purpose of blending is to get a blended as fired coal having ash, volatile matter and gross calorific value close to design coal and the two coals are to be blended in such ratio proportions that resultant coal blend have desired ash, volatile matter and gross calorific value [3]. For a coal to be blended certain parameters have to be considered to get compatibility with respect to combustibility ( Burn ability) of coal, grindability ( HGI), ash fusion behavior, swelling characteristics of coal, need to be checked"

Jan 1, 2017